Quantification of bryophyte community dynamics along the transects measured, showed that the three Windmill Islands moss species, Bryum pseudotriquetrum, Grimmia antarctici, and Ceratodon purpureus, and the liverwort, Cephaloziella exiliflora, have differences in their relative distributions. Grimmia antarctici and B. pseudotriquetrum, the two most abundant species, show opposite abundance trends along the transects: G. antarctici increases in abundance with increasing distance along the transects, while B. pseudotriquetrum decreases. Ceratodon purpureus, and the liverwort, C. exiliflora, present at lower levels of abundance, respond in the same direction as B. pseudotriquetrum, decreasing in abundance with increasing distance along the transects.

These relative species distribution patterns have significant implications for the quantification of Windmill Islands community dynamics in response to climate change. With respect to the Windmill Islands three moss species, research shows that the physiological tolerance of desiccation is greatest in C. purpureus and lowest in the Antarctic endemic, G. antarctici (Robinson, Wasley et al. 2000). The relative species distribution patterns we have found support these physiological responses: C. purpureus is most abundant in higher, drier, areas, while G. antarctici is highest in abundance in lower, wetter, areas. The status of future water availability in the Windmill Islands is unclear. Currently the Windmill Islands are undergoing a drying trend, due to isostatic uplift associated with deglaciation. The influence of future climate warming has the potential to offset this drying trend if increases in precipitation occur. Water availability for plant growth, in the Windmill Islands, will only increase, however, if precipitation levels both offset the current drying trend and also exceed the predicted increase in snow and ice melt associated with warmer temperatures. Based on our current knowledge of the physiological response of the Windmill Islands bryophyte species, combined with what we now know of their relative distributions, under increasingly wet conditions, we predict an increase in the extent of G. antarctici, and under drying conditions, a relative decline in G. antarctici and an increase the relative dominance of C. purpureus.